Having heard Clinic’s second album, 2002’s Walking With Thee, before ever knowing the Liverpool four-piece wore surgical masks onstage, once I did, I never thought of the costumes as a gimmick. People might tend to picture something along the lines of Slipnot, the beloved nerdy uniformity of Devo’s hats or even the punk meets B-movie aesthetic of the Mummies, but Clinic somehow always wore the masks with dignity as they melded a musically proficient tight performance with a contagious live energy at their shows. (I’ll spare you the obvious contagion pun.)

At the Bell House Monday night, the substitution of their scrubs for dashikis, then paired with the trademark masks, might have suggested a wacky vibe, but the band revealed a mellower sound when providing a preview of their new album, Bubblegum, slated for release in October. While still worlds away from bland, the gentleness of first single “I’m Aware” is a departure from the fast-paced post punk mantras and quirky keyboard sounds that they have long made their stock-in-trade. The slightly psychedelic hues of songs such as “Milk & Honey” and “Baby” were hinted at previously with cuts like “The Witch (Made to Measure)” (from 2008’s Do It!), but perhaps not the quiet dreaminess of “Linda,” which vocalist Ade Blackburn performed solo with an acoustic guitar.

Blackburn’s voice veered wildly from a whisper to a croon on the thumping “Welcome” (from Walking With Thee) in betweens bursts of melodica. Another standout was “I.P.C Subeditors Dictate Your Youth,” from the band’s first EP, as was the primitively eerie run through “Harvest” (from 2006’s Visitations). Clinic exited the stage and reappeared for a quick encore, closing the show with “Orangutan,” one of Bubblegum’s more spirited moments.

While Blackburn, bassist Brian Campbell, guitarist Jonathan Hartley and drummer Carl Turney still create a mesmerizing live dynamic at times, it was off-putting at best hearing the new record for the first time. Sure, this was their first North American tour date, but the new sounds didn’t mesh with the old, and the show lacked the band’s usual flawless continuity. Perhaps, as the title suggests, this new record needs to be chewed on for a bit before being appreciated.